astronomy is a nocturnal activity 1953, t. e. houck and a. d. code
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Astronomy is a nocturnal activity
1953, T. E. Houck and A. D. Code
The sky above us
Stars dominate the night sky
• Relative positions of stars remains fixed• The whole pattern revolves around us• Constellations – patterns in star
distribution• Constellations vary – related to mythology• Constellations not real• 1929 IUA – 88 official constellations• Every star belongs to a constellation
Orion Constellation
Map of Orion Constellation
The wanderers
• Sun, Moon, planets move relative to stars
• Wander in a narrow band – Zodiac
• Ecliptic
The Zodiac
The Ecliptic
The Celestial Sphere
23.5
Earth’s prograde rotation
Ursa Minor
Precession of Earth’s spin
26,000 years period
Equatorial Coordinates
Examples
• Orion:
• Right Ascension: 5 hours
• Declination: 5 degrees
• Ursa Major = Saptarshi Mandal
• The Great Bear (Big Dipper)
• Right Ascension: 11 hours
• Declination: 50 degrees
Image Sources
Image Sources
http://fourmilab.ch/yoursky/
Image Sources
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